One of the best tools that you have as gardeners to help us figure out your gardening schedule is the USDA zone info. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

It's possible to estimate when it's the best time to plant liatris by checking out the USDA zone info for Roma.

Planting Calendar for Liatris

Frost tolerance for liatris:	Very tolerant of frost.
When to plant:	Up to 7 weeks before last frost.

You can plant liatris much earlier in the year because they do well in cold.

The earliest that you can plant liatris in Roma is January. However, you really should wait until February if you don't want to take any chances.

The last month that you can plant liatris and expect a good harvest is probably October. You probably don't want to wait any later than that or else your liatris may not have a chance to grow to maturity. Starting your liatris indoors is a great way to get them started a few weeks earlier.

Last Frost Date

On average the last frost when the weather gets warmer is on February 15 in Roma. It might get as low as 25°F during the coldest months of winter.

Since the USDA zone info for Roma is an average the actual date of last frost can change quite a bit from year to year. Half of the time in Roma it frosts late in the year after February 15 so be sure to be ready to cover your liatris if you have a surprise late frost.

USDA Zone Info for Roma

Here is the info for USDA Zone 9b.

Average Date of Last Frost (spring)	February 15
Average Date of First Frost (fall)	December 15
Lowest Expected Low	25°F
Highest Expected Low	30°F

This means that on a really cold year, the coldest it will get is 25°F. On most years you should be prepared to experience lows near 30°F.

Plants to Grow in Roma

You may be interested in your other planting guides for Roma.